scholarly journals Topology Optimization Based Parametric Design of Balloon Borne Telescope’s Primary Mirror

2021 ◽  
Vol 11 (11) ◽  
pp. 5077
Author(s):  
Fengchang Liu ◽  
Wei Li ◽  
Weiguo Zhao ◽  
Haibo Zhao ◽  
Guanyu Lin ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Fundamental Frequency ◽  
Parametric Design ◽  
Optimal Solution ◽  
Optical Element ◽  
Compromise Programming ◽  
Programming Method ◽  
Surface Error ◽  
Primary Mirror ◽  
Overall Performance

For balloon-borne telescopes, the primary mirror is the most important optical element, but designing a primary mirror with an excellent overall performance is a challenge. To comprehensively consider the contradictory objectives of the root mean square (RMS) surface error under gravity in the X and Z directions, the mass and fundamental frequency of the primary mirror, a parametric primary mirror design using the compromise programming method based on topology optimization is proposed. The parametric design of the compromise programming method based on topology optimization is used to find the optimal solution for X-direction RMS (RMSx), Z-direction RMS (RMSz), mass, and fundamental frequency. Compared with the initial primary mirror structure designed according to traditional experience, the overall performance is improved. Results show that the respective mass of the primary mirror, the RMSx and the RMSz decreased by 8.5%, 14.3% and 10.5% compared to those before optimization. Comprehensive consideration can prove the effectiveness of parametric design based on the topology optimization of the primary mirror. This method provides a reference for the design of other primary mirrors for balloon-borne telescope and space cameras.

scholarly journals Topology Optimization of Automotive sheet metal part using Altair Inspire

2020 ◽  
Vol 5 (3) ◽  
pp. 143-150
Author(s):  
Netsanet Ferede
Keyword(s):  
Topology Optimization ◽  
Sheet Metal ◽  
Optimization Problem ◽  
Optimal Solution ◽  
Sheet Metal Part ◽  
Metal Part ◽  
Solution Quality ◽  
Design Engineers ◽  
Automotive Sheet ◽  
Reduced Costs

In an optimization problem, different candidate solutions are compared with each other, and then the best or optimal solution is obtained which means that solution quality is fundamental. Topology optimization is used at the concept stage of design. It deals with the optimal distribution of material within the structure. Altair Inspire software is the industry's most powerful and easy-to-use Generative Design/Topology Optimization and rapid simulation solution for design engineers. In this paper Topology optimization is applied using Altair inspire to optimize the Sheet metal Angle bracket. Different results are conducted the better and final results are fulfilling the goal of the paper which is minimizing the mass of the sheet metal part by 65.9%  part and Maximizing the stiffness with Better Results of Von- Miss Stress Analysis,  Displacement, and comparison with different load cases.  This can lead to reduced costs, development time, material consumption, and product less weight.

scholarly journals Nonpreemptive Goal Programing Method in Optimization Nurse Scheduling by Considering Education Level

2021 ◽  
Vol 22 (2) ◽  
pp. 85
Author(s):  
Fitriani Utina ◽  
Lailany Yahya ◽  
Nurwan Nurwan
Keyword(s):  
Goal Programming ◽  
Undergraduate Education ◽  
Optimal Solution ◽  
Education Level ◽  
Programming Method ◽  
Nurse Scheduling ◽  
Optimal Service ◽  
Schedule Design ◽  
Good Nurse ◽  
Better Than

Nurse scheduling is one of the problems that often arise in hospital management systems. Head of ICU room and nurse to cooperate in making good nurse scheduling for the creation of optimal service. In this paper, we study a hospital nurse schedule design by considering the level of nurse education and the provision of holidays. Nurses with undergraduate education (S1) Nurses become leaders on every shift and are accompanied by nurses with diploma education (D3). The scheduling model in this study using the nonpreemptive goal programming method and LINGO 11.0 software. The preparation of the schedule of nurses assigned to this method can optimize the need for efficient nurses per shift based on education level. The data in the research was obtained by collecting administrative data at Aloei Saboe Gorontalo hospital. The data used are the published schedule by the head of the ICU room. In making a nurse schedule, there are limitations to consider such ashospital regulation. The results of the study obtained an optimal solution in the form of meeting all the desired obstacles. Computational results shows that nurse scheduling using the nonpreemptive goal programming method and LINGO 11.0 software better than the schedule created manually. Every shift is a maximum of one leader with an undergraduate education (S1) background and accompanied by a nurse with a diploma education (D3) background. Keywords: scheduling, goal programming, nonpreemptive goal programming.

Parametric Design of Flexure Supporting for Optical Space Remote Sensor Primary Mirror

2016 ◽  
Vol 36 (11) ◽  
pp. 1128001 ◽  
Author(s):  
Hu Jianing ◽  
Dong Jihong ◽  
Zhou Pingwei
Keyword(s):  
Parametric Design ◽  
Primary Mirror ◽  
Remote Sensor

The Surface Error Analysis of Theodolite Primary Mirror Considering Contact Boundary Condition

2014 ◽  
Vol 43 (12) ◽  
pp. 1212004
Author(s):  
谢军 XIE Jun ◽  
曹立华 CAO Li-hua ◽  
韩光宇 HAN Guang-yu ◽  
乔健 QIAO Jian ◽  
刘永明 LIU Yong-ming ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Error Analysis ◽  
Contact Boundary ◽  
Surface Error ◽  
Primary Mirror

Optimal shape design of a brake calliper for squeal noise reduction considering system instability

2010 ◽  
Vol 224 (7) ◽  
pp. 909-925 ◽  
Author(s):  
H J Soh ◽  
J-H Yoo
Keyword(s):  
Topology Optimization ◽  
Design Process ◽  
Optimization Design ◽  
Parametric Design ◽  
Unstable Mode ◽  
Complex Eigenvalue ◽  
Noise Generation ◽  
Design Variables ◽  
Asymmetric Shape ◽  
Squeal Noise

Squeal is a noise phenomenon occurring in the last stage of automobile braking with a high-frequency sound. It is very difficult to express the phenomenon using a mathematical model, since the origin of squeal noise is physically complex. However, the possibility of squeal generation can be predicted by solving the vibration equation of the self-excited system using the complex eigenvalue analysis method. The results of the method are expressed as the magnitude of the unstable mode, and the generation of squeal noise can be prevented by reducing the magnitude of the unstable mode of the brake system. The objective of this research is to determine the optimal design process focused on the calliper housing shape to suppress squeal noise generation by reducing the system instability. The objective function is set to minimize the real part of the complex eigenvalue, i.e. the instability index. In the optimization design process, the design variable for topology optimization is established by focusing on the finger part of the calliper housing, which transmits the braking pressure to the pad lining. To supplement the complex shape generated by the topology optimization process, parametric design variables are selected for the subsequent process. Parameters are set to adjust the housing finger stiffness and are defined by considering the topology optimization result. Finally, the asymmetric shape of the calliper housing is obtained to reduce squeal noise generation.

Role of Fundamental Frequency Differences in the Perceptual Separation of Competing Vowel Sounds by Listeners With Normal Hearing and Listeners With Hearing Loss

1997 ◽  
Vol 40 (6) ◽  
pp. 1434-1444 ◽  
Author(s):  
Kathryn Hoberg Arehart ◽  
Catherine Arriaga King ◽  
Kelly S. McLean-Mudgett
Keyword(s):  
Hearing Loss ◽  
Fundamental Frequency ◽  
Normal Hearing ◽  
Average Increase ◽  
Identification Task ◽  
Vowel Identification ◽  
Overall Performance ◽  
The Mean ◽  
Perceptual Separation

This study compared the ability of listeners with normal hearing and listeners with moderate to moderately-severe sensorineural hearing loss to use fundamental frequency differences (ΔF 0 ) in the identification of monotically presented simultaneous vowels. Two psychophysical procedures, double vowel identification and masked vowel identification, were used to measure identification performance as a function of ΔF 0 (0 through 8 semitones) between simultaneous vowels. Performance in the double vowel identification task was measured by the percentage of trials in which listeners correctly identified both vowels in a double vowel. The masked vowel identification task yielded thresholds representing signal-to-noise ratios at which listeners could just identify target vowels in the presence of a masking vowel. In the double vowel identification task, both listeners with normal hearing and listeners with hearing loss showed significant ΔF 0 benefit: Between 0 and 2 semitones, listeners with normal hearing showed an 18.5% average increase in performance; listeners with hearing loss showed a 16.5% average increase. In the masked vowel identification task, both groups showed significant ΔF 0 benefit. However, the mean benefit associated with ΔF 0 differences in the masked vowel task was more than twice as large in listeners with normal hearing 9.4 dB) when compared to listeners with hearing loss (4.4 dB), suggesting less ΔF 0 benefit in listeners with hearing loss. In both tasks, overall performance of listeners with hearing loss was significantly worse than performance of listeners with normal hearing. Possible reasons for reduced ΔF 0 benefit and decreased overall performance in listeners with hearing loss include reduced audibility of vowel sounds and deficits in spectro-temporal processing.

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